int f(int n)
{
    return n&1;
}
int main()
{
    int a=3,b=4;
    a=a+b;/**a=7 b=4*/
    b=a-b;/**a=7 b=3*/
    a=a-b;/**a=4 b=3*/
    printf("%d %d\n",a,b);

    a=3,b=4;
    a=a^b;
    b=a^b;
    a=a^b;
    printf("%d %d\n",a,b);

    a=3,b=4;
    a^=b^=a^=b;
    printf("%d %d\n",a,b);


    int A[2]={3,4};
    A[0]^=A[1]^=A[0]^=A[1];
    printf("%d %d\n",A[0],A[1]);

    return 0;
}
